Rotary pump



A. IZBICKI ROTARY PUMP March 7, 1933.

Filed Dec. 5, 1929 2 Sheets-Sheet 1 March 7, 1933.

ROTARY PUMP Filed Dec. 5, 1929 2 Sheets-Sheet 2 13 v. Ive 26 re 1Z- 1 VEIYTOR A. IZBICKI 1,900,416

Patented Mar. 7, 1933 UNITED STATES 1mm: rzmcxr, or CAMBRIDGE, MASSACHUSETTS ROTARY PUMP Application filed December 5, 1929. Serial 110.411,?80.

This invention relates to rotary pumps of the eccentric rotor type. a

While pumps of this type are old and well known, their use has been restricted by certain objections to. them, more especially'the intermittent orpulsating character of their action,and the difiiculty of preventing leakage between the'intake and exhaust sides of the pump. The present invention deals particularly with these problems and aims to devise a thoroughly. practical solution for them.

The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawings, and the novel features will be particularly pointed out in the appended claims.

In the drawings, I A s Figure 1 is a plan view of a pump'cmbodyin this invention; Fig. 2 is a vertical, sectional line 22, Fig. 1; r I

Fig. 3 is a horizontal, sectional view on the line 33, Fig.2; Fig.4 is va vertical, sectional view onthe line 4-4, Fig. 1; and 7 Fig. 5 is a vertical, sectional view on the line 5 -5, Fig. 2'. V g

The pump construction shown comprises a casing which includes a body 2, a front plate 3, and a rear plate 4, these plates beingtbolted to the front and rear sides, respectively, "of

view on the the body. 'In the body of the casing are two parallel cylindrical chambers 5 and 6, respectively, positioned closely adjacent to; but spaced from each other. A guideway 7 connects the chambers. Eccentric rotors are mounted in the respective chambers. In the preferred form of the invention shown in the drawings each rotor consists of an eccentric and a sleeve closely encircling it. These eccentrics are indicated at 8 and 9, respective:

ly, and their cooperating sleeves are shown at 10 and 11.

The eccentrics are keyed to shafts 12 and 13, respectively, which extend through tubular extensions 14 and 15 preferably formed integral with the back plate 4. Gears 16 and 17 keyed to the respective shafts and mesh mounted in the same manner.

2 that the rotors are mounted oppositely or ing with each other cooperate with the shafts to revolve the rotors. Referringto 3 it will be observed that the shaft 12 is sup- I portedinbushings18 and '19, the former being mounted in the tubular extension 14 while the latter is secured in a recess'in the front plate 3. The former bushing118 fits snugly but 'slidably in the part 14, and its forward end bears against a packing 20 which closely encircles the shaft, while its rearwardend' is backed up by a packing gland'or sleeve 21 which is threaded into the outer end of the tubular. extension 14. By turning this sleeve inwardly the bushing '18 may be forced in far enough .to firmly compress the packing 20 and prevent any leakage around the shaft. Y The other shaft 13 is It will be seen from aninspection of Fig.

0 180 apart, and it will also be evident that since their shafts are geared together the mtors will revolve in opposite directions. The ,7 dimensions ofthe cylinders androtors are such that the rotors simply have a good rune ning fit in the cylinders or chambers. Con necting the two rotors is a slide 24',Whi0li fits snugly in the guideway'7, and the opposite ends of this slide are held constantlyin engagement with the rotorsasthey revolve, the slide being moved backward and forward through the guideway dueto'this arrangement. Preferably the sleeves 10 and .11 of the rotors have an interlocking engagement with the oppositeends'of the slide 24 so that the sleeves are both held against rotation with their respective eccentrics; This interlocking engagement preferably is made by vform- I ing teeth on the opposite ends of the slide similar to the teeth of a rack and making corresponding teeth on the sleeves 10and 11 to fit the teethof the slide. Such aconstruc tion permits the up anddown movementof the two sleeves relatively to the slide as the eccentrics revolve while still maintaining un- 95 disturbed the engagement of the slide with the sleeves. V

The slide also is used to controlithe communication between the cylinders or cham-j bers 5 and 6 and the intakeport. This port ports or passages 27 and 28, best shown in- Figs. 4 and 5, into a common exhaust portor discharge outlet 29. .The'passagesl27 and 28 are also equipped with independentcheck valves 30 and 31 of some suitable form, those shown consisting simply of small plates held down lightly by leaves of a spring 32 secured to the bottom of the cap 33 in which the greater part of the main exhaust passage 29 is formed.

It will now be clear that when this pump is in operation each rotor acts as a single pumping unit, the fluid being drawn into one cylinder through the intake 25 and chamber 26, and forced out through the exhaust passages for that particular cylinder. As one cylinder stops taking fluid from the intake 25 the other begins, so that a substantially continuous pumping action is produced. The gas or liquid pumped is forced through the exhaust passages, past the check valves 27 and 28,

which lift very easily, and into the main exhaust passage. Since the check valves are located closely adjacent to the respective ro tor chambers, and the passages in which they are located open into these chambers very close to the slide 24, the fluid taken into either chamber during a part of each revolution of the rotor in that chamber is forced very completely out of the chamber during a subsequent portion of the same revolution. 'Due'to the peculiar interlocking engagement of the ends of the slide 24 with the sleeves 10 and 11, leakage between the high and low pressure sides of either chamber is reduced to a minimum, assuming,of course, that proper care is taken in manufacturing the parts to produce good running fits. A normal quantity of oil or other lubricants a sists materially also in sealing the contact sur faces against leakage. The effectiveness of this seal between the high and low pressure sides of each pumping unit is greatly increased by the toothed connection between the slide 24 and the eccentric sleeves 10 and 11 due to thefact that this toothed formation provides a'series of contact lines between each eccentric and the slide through which any leaking fluid must pass. At the same time this construction permits the freeup and down movementof both sleeves 10 and 11 as their centers rise and fall relatively to the slide during the revolution of the rotors. It will be seen from an inspection of Fig. 2

that the slide has a width equal to more than twice the eccentricity of either of the eccentrics 8 or 9. In other words, the width of the slide is greater than twice the distance between the center of each eccentric and its driving shaft. Consequently, the operative engagement of the toothed portions of the sleeve with the ends of the slide is maintained constantly as the sleeves move up and down during their rotation. Furthermore, this engagement is maintained'without theuse of anysprings, or the like, which would exert a frictional drag on the movement of the rotors. f

. While I have herein shown and described apreferred embodiment of my invention, it will be'clear that the invention may beembodied. in other forms without departing from the spirit or scope thereof. V

Having thus described my invention, what I desire to'claim as new'is:

1. In a rotary pump, the combination of a casing having two approximately parallel cylindrical chambersthereinlocated side by side and "closely adjacent to each other with a guideway connecting them'at' their points of closest, approach to each other, twoeccentries mounted, respectively, in'sa'id chambers, sleeves encircling the respective eccentrics, driving means for rotating said eccentrics in a fixed relationship to each other, a rigid slide fitting snugly in said guideway for re ciprocating movement therethroughin' -a fixed path, the opposite end faces'of said slide each being provided with a plurality of teeth. andsaid sleeves each having a plurality of similar teeth fitting between the teeth on .the ends of said slide, whereby the sleeves can move up and down relatively to said slide while their engagement with the slide remains uninterrupted, and intakeand exhaust ports for said chambers. 2. In a rotary pump, the combination of a casing having two approximately parallel cylindrical chambers therein locatedside by side and closely adjacent-to each otherwith a guideway connecting-them at their points of closest approach toeach other, two eccentrics mounted, respectively, in said chambers,

sleeves encircling the respective eccentrics,

driving means for rotating said eccentrics in a fixed relationship to each other, a rigid slide fittingsnugly in said guideway for reciprocating movement 7, therethrough in a fixedlpath, the opposite end faces ofsaid slide each being provided with a plurality of teeth and said sleeves each having a plurality ofsimilar teeth, fitting between the teeth on the ends of said slide, whereby the sleeves can moveup and down relatively to said slide while their engagement withthe slide remains uninterrupted, and intake and eX- haust passages for conducting fluids to and from said chambers, said slide controlling the communication between said intake passage and both of said chambers. V

3. In a rotary pump, the combination of a casing having two approximately parallel cylindrical chambers therein located side by side and closely adjacent to each other with a guideway connecting themrat their points of closest approach to each other, two eccentrics mounted, respectively, in said chambers, sleeves encircling the respective eccentrics, driving means for rotating said eccentrics in a fixed relationship to each other, a rigid slide fitting snugly in said guideway for reciprocating movement therethrough in a fixed path, the opposite end faces of said slide each being provided with a plurality of teeth and said sleeves each having a plurality of similar teeth fitting between the teeth on the ends of said slide, whereby the sleeves can move up and down relatively to said slide while their engagement with the slide remains uninterrupted, an intake passage opening into said guideway, said slide on one end face thereof, and said sleeve havside thereof adjacent to said passage to communicate with said passage for controlling the communication between said cylinder and said passage, and an exhaustpassage for said cylinder at the opposite side of said slide.

- ADOLPH IZBICKI.

having a recess in the side thereof adjacent to said passage for causing it to control communlcatlon between said passage and both chambers and to open said chambers alternately to said passage, and an exhaust passage communicating with saidchambers.

4. In a pump, the combination of a casing having an approximately cylindrical chamber therein, an eccentric mounted to revolve in said chamber, a sleeve closely encircling said eccentric and in which the eccentric rotates, the dimensions of said sleeve and said chamber being such that the eccentric maintains a part of said sleeve substantially constantly in engagement with the wall of said chamber as the eccentric revolves, a guideway in said casing leading radially from said chamber at one side thereof, a slide fitting snugly in said guideway to reciprocate therein, said slide having a series of teeth on one end face thereof, and said sleeve having a series of similar teeth fitting between the teeth on said slide, means for maintaining the teeth of said slide and said sleeve constantly in mesh with each other and inlet and exhaust passages for conducting fluid toward and from said cylinder, said passages being located at opposite sides of said slide.

5. In a pump, the combination of a casing having an approximately cylindrical chamber therein, an eccentric mounted to revolve in said chamber, a sleeve closely encircling said eccentric and in which the eccentric rotates, the dimensions of said sleeve and said chamber being such that the eccentric maintains a part of said sleeve substantially constantly in'engagement with the wall of said chamber as the eccentric revolves, a guideway in said casing leading radially from said chamber at one side thereof, a slide fitting snugly in said guideway to reciprocate 

